*{padding:0;margin: 0;}
/*body{background-image: url(images/bg.jpg) no-repeat;}*/
.back{margin: 0 auto;width: 1200px;height: 1380px;border: 1px solid red;background: #D6F0F1;position: relative;}
.back .main{width: 892px;height: 1380px;margin: 0 auto;border: 1px solid red;position: absolute;z-index: 2;left: 160px;}
.back .mg{position: absolute;z-index: 1;left: 160px;}
h3{}